US3025940A - Line lock apparatus - Google Patents

Description

March 1952 R. E. WHEELER 3,025,940

LINE LOCK APPARATUS 2 Sheets-Sheet 1 Fig./

Filed Feb. 25, 1961 INVENTOR REYNOLD E. WHEE ER ATTORNEYS March 20, 1962 R. E. WHEELER 3,025,940

LINE LOCK APPARATUS Filed Feb. 23, 1961 2 Sheets-Sheet 2 Fig.2

INVENTOR REYNOLD E. WHEELER ATTORNEYS aired rates free 3,025,940 LINE LUCK APPARATUS Reynold E. Wheeier, Farmington, Conn, assignor to Royal McBee (Jorporation, Port Chester, N.Y., a corporation of New York Filed Feb. 23, 1961, Ser. No. 91,266 Claims. (Cl. 197-47) This invention relates to a novel line lock arrangement for business machines, and more particularly relates to a novel arrangement for disabling the keyboard of an electric typewriter or the like.

In many conventional electric typewriters a line lock bar is adapted to be moved into underlying relation with respect to a portion of each of the various key levers of the machine that are to be locked up so as to thereby make it impossible to depress these key levers. In this manner the keyboard of the typewriter may be disabled at times, such as during a carriage return movement, when it is desired to prevent the advertent or inadvertent depression of the keys. In previously used mechanisms of this type the parts can easily get out of adjustment and sometimes it is possible to break through the detentin-g action of the line lock and thereby get an undesired operation of one of the power operated linkages of the typewriter. The instant line lock arrangement contemplates avoiding these and other difficulties by providing a keyboard disabling means which, although allowing a depression of the various keys, does not permit such key depressions to initiate or trigger power strokes of the respectively associated power driven linkages.

One object of the instant invention is to provide a simple and inexpensive line lock arrangement which is reliable and efficient.

Another object of the invention is to provide a novel line lock arrangement for typewriters whereby the normal dip of a key is rendered inoperative to initiate a power action of the machine.

Another object of the invention is to provide a line lock arrangement for typewriters whereby the respective non-repeat or by-pass element of each type action may be controlled so as to make impossible the initiation of any power stroke of the associated type bar in response to a depression of the associated key lever or other control element.

A further object of the invention is to provide a common line lock bail means for an electric typewriter whereby displacement of said bail means to an inoperative condition occurs in response to the depression of the related key lever of the machine.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIGURE 1 is a side elevational view showing the normal condition of the instant line lock arrangement.

FIGURE 2 is a perspective view of the general line lock apparatus.

FIGURE 3 is a side elevational view showing an active condition of the apparatus of FIGURE 1.

Although the instant invention is shown and described in conjunction with a type action of the type used in the electric typewriter presently being produced and marketed by the Royal McBee Corporation it will be understood that the instant line lock arrangement may be employed with the various other types of power driven linkages. Unless otherwise indicated it will be assumed that the various parts discussed are suitably supported in a conventional manner in the machine frame.

The above mentioned type action will be briefly reviewed with reference to FIGURES 1 and 2. This action essentially comprises a type bar linkage 8, a continuously rotating power roll 9 and a key control linkage 10. The type bar linkage 8 includes a pivotally mounted bell crank 11 which is articulately connected to a related type bar through a link 12 and which is pivotally connected to an action plate 13 that rotatably mounts a pawl 14 and a pawl latch 15. Latch 15 is biased in a clockwise direction by means of a spring 16 so as to normally releasably retain the pawl 14 in a counter clockwise or inoperative position against the action of its biasing spring 17 and away from operative engagement with the said rotating power roll 9. The key control linkage 10 comprises a pivotally mounted key lever 20 which is adapted to rotatably actuate a pivotally supported bell crank 21. Rotatably mounted on the rearward end of bell crank 21 is a by-pass element or non-repeat dog 22 which is yieldably biased by means of a spring 23 to a normal clockwise position determined by engagement of the dog projection 24 with a bent over ear 25 formed on the adjacent portion of said bell crank 21. The lower end 26 of the non-repeat dog 22 overlies a shelf 27 formed on the adjacent end portion of said pawl latch 15. As is well understood a typing action is initiated by depressing the key lever so as to thereby cause the pawl latch 15 to release pawl 14 for movement into engagement with the rotating power roll. Thereafter the type bar linkage is driven through a power operated printing stroke in the usual manner and will be returned to normal position by the action of the usual type bar return spring means. If the key lever is held depressed during this typing action then the rearward edge of the said latch shelf 27 will during its return or rearward movement cause the bypass element or non-repeat dog 22 to be pivotally displaced to an inoperative counter clockwise position thereby requiring the release or elevation of the key lever before another typing action may be initiated. The construction and operation of the above described and related equipment is conventional in nature and need not be further particularlized here.

This conventional type apparatus is modified and supplemented in the following manner. Fixedly mounted on the machine side frames is a pair of axially aligned stub shafts 30 and 31 which rotatably mount the respective ends of a bail 32. Bail 32 is provided with a body portion 33 which is adapted to be swung into and out of underlying relation with respect to a lug 34 formed on the by-pass element 22 of each of the normal complement of type and service actions of the typewriter. The bail body portion 33 is normally lightly biased by means of a spring 35 to a counter clockwise or inoperative position, shown by the dotted lines in FIGURE 1, determined by engagement of the right end, FIGURE 3, of the bail 32 with a bent off ear 36 formed along the upper forward edge of a lever 37. The lever 37 is pivotally mounted on the machine frame by means of a stud shaft 40 and is biased by means of a spring 41 towards a normal clockwise position determined by engagement with a stud 4-2 fixed to the machine frame.

Two separately operable linkages are provided for displacing the bail 32 from an inoperative position to the operative position as shown by the solid lines in FIG- URES l and 2. The first of these two linkages is a manually operated arrangement comprising a link 43 which is articulately connected between a slot 44 formed in the left end, FIGURE 2, of the bail 32 and the on-oif switch control lever 4-5 that is pivotally mounted on the machine frame by means of a stud shaft 46. The lever 45 is operatively connected to the power supply switch of the typewriter by the usual linkage 47, 50., etc., which is provided with any suitable type of detent arrangement such as illustrated at 51 so that said lever 45 may be yieldably retained in either the on or off position. When the switch control lever is in its on position the spring 35 will retain the bail 32 in its inoperative position shown by the said dotted lines of FIGURE 1, so that the bail body portion 33 lies out of the path of move ment of the by-pass lugs 34 and hence cannot interfere with normal operation of the various type actions, of the machine. When the lever 45 is moved to its ofi position, as illustrated in FIGURES l and 2, the bail body portin'33 will be swung into underlying relation with respect to all of the lugs such as 34. Thereafter when any key lever is depressed the associated lug 34 will first engage the body portion 33 of the bail and then will be cammed or swung to an inoperative position in response to the depression of said key lever as illustrated in FIG- URE 3. Under these conditions it will be apparent that when the power supply switch is off depression of any of the various key levers will serve only to displace the related by-pass elements to inoperative positions and will not initiate a power stroke of the associated typing or service actions of the typewriter. Restoration of the lever 45 to the on position will permit spring 35 to return bail 32 to its normal or inoperative position.

The second linkage for swinging the bail 32 from its normal inoperative position to an operative comprises a link 52 which is articulately connected between the said lever 37 and an arm 53 of the power operated linkage 54- which serves to effect the return movement of the typewriter carriage. In that the construction and operation of linkage 54 is conventional in nature it need not be further detailed here. Suifice it to say that when a carriage return operation is initiated the arm 53 will be displaced in a counter clockwise direction, FIGURE 2, and when this movement occurs it will serve to swing lever 37 in a counter clockwise direction, FIGURE 2, away from its normal position so as to thereby displace said bail 32 to its said operative position; the movement of bail 32 in such cases being accommodated by the slot 4'4 in the left end, FIGURE 2, of said bail. Restoration of the linkage 54 to its normal FIGURE 2 position will permit spring 35 to again return bail 32 to its normal or inoperative position.

An adjustment in the pivot point for the bail 32 and a slight increase in the clockwise extent of the throw or stroke of the bail body portion 33 may be provided where it is desired to have the terminal portion of the counter clockwise stroke, FIGURE 1, of said bail serve to directly swing the by-pass elements such as 22 to their counter clockwise or inoperative positions.

While several embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that a numerous variations and modifications may be made in the particular construction without departing from the underlying principles of the invention. It is therefore desired, by the following claims to include within the scope of the invention all such variations and modifications whereby substantially the results of the invention may be obtained by the use of substantially the same or equivalent means.

The invention claimed is:

1. In a typewriter having a power operated linkage, a power driven member for actuating said linkage, and a control linkage operable to cause engagement of said power operated linkage and said driven member, said control linkage having by-pass means for preventing more than one operation of said power operated linkage for each operation of said control linkage; the improvement comprising means conditionable for cooperation with said by-pass means to render the same inefifective when said control linkage is operated.

2. In a typewriter having a type bar linkage, a power roll for actuating said type bar linkage, and a key control linkage operable to couple said type bar linkage and power roll, said key control linkage including a bypass means for preventing a repeat actuation of said type bar linkage for each depression of said key control linkage; a line lock arrangement comprising a bail means movable from a normal inoperative position to an operative position for moving said by-pass means to its displaced condition whereby operation of said key control linkage will be ineffective to couple said type bar linkage to said power roll, and control means for operating said bail means.

3. Apparatus as defined by claim 2 wherein said control means comprises a manually operable lever adjacent the keyboard of the typewriter.

4. Apparatus as defined by claim 2 wherein said control means comprises a linkage which is operated in response to the initiation of a return movement of the carriage of the typewriter.

5. Apparatus as defined by claim 2 wherein said bail means in moving to its operative position engages said by-pass means and displaces the latter to an inoperative position.

6. Apparatus as defined by claim 2 wherein said bail means when in an operative position is adapted to be engaged by said by-pass means and the latter is moved to an inoperative condition in response to the normal operative movement of said key control linkage.

7. In a typewriter having a type bar linkage, a continuously driven power roll, and a key control lever operative to effectively couple said type bar linkage and said power roll, said key control linkage including a by-pass means for preventing more than one operative printing stroke of said type bar linkage for each depression of said key control linkage; the improvement comprising independent control means conditionable for displacing said by-pass means to an inoperative position so as to prevent the initiation of a power stroke of said type bar linkage.

8. Apparatus as defined by claim 7 wherein said independent control means when in an operative position is adapted to be engaged by said by-pass means so that the latter is displaced to an inoperative condition in response to the normal dip movement of said key control linkage.

9. In a typewriter having a plurality of type bar linkage, a continuously rotating power roll, and a plurality of selectively operable 'key control linkages which are respectively adapted to effectively couple a related one of said type bar linkages to said power roll, each of said key control linkages having a by-pass element which is operative to prevent a repeat action of the associated type bar linkage in response to a single operation of the associated key control linkage; the improvement comprising a common bail means movable from a normal inoperative position to an operative position wherein it lies in the operative path of travel of said by-pass element whereby operation of any of said key control linkages will cause said by-pass element to engage said bail means and to be cammed to an inoperative position which prevents the effective coupling of the related type bar linkage and said power roll.

10. Apparatus as defined by claim 9; additionally comprising control means for moving said bail means, one portion of said control means being manually operable and another portion thereof being operated in response to the initiation of a return movement of the carriage of the typewriter.

No references cited.

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